1. Field of the Invention
The present invention relates to a controllable production well packer. In one aspect, it relates to a petroleum production well packer comprising an electrically powered device, in which the device may comprise an electrically controllable valve, a communications and control module, a sensor, a modem, a tracer injection module, or any combination thereof.
2. Description of the Related Art
Petroleum wells (e.g., oil and/or gas wells) typically pass through formations containing multiple zones that may produce differing fluids, as well as impermeable zones. The fluid-bearing zones may produce saline or clear water, oil, gas, or a mixture of these components.
It is desirable and customary to maintain hydraulic isolation between zones so that the fluids produced from each zone may be received separately at the surface. Even if a particular zone is not producing petroleum products, it is usually necessary to ensure that fluids from that zone do not travel to other zones using the wellbore as a transport path, and to avoid contamination of the fluids in each zone.
The necessary isolation between zones is often provided by packers. A typical hydraulically set production packer of the prior art is schematically shown in FIG. 1. Packers are mechanical devices that close the annulus between the production tubing and the casing, and seal to both. Packers are typically installed at the time of well completion by attaching them to a tubing string as it is lowered into the well. Thus, during placement, the packer must pass freely within the casing. Once it is in place, a hydraulic actuator (energized and controlled from the surface) operates the sealing mechanism of the packer, which clamps the packer to the casing and effects a fluid-tight seal in the annular space between the tubing and the casing.
Packers may provide complete isolation between the annular spaces above and below them, or may be equipped with one or more preset mechanically-actuated valves to control flow past them. When control valves are included, however, their settings can only be altered by mechanically inserting a slick-line tool, which is inconvenient, slow, and relatively costly. Additionally, when there are multiple zones and multiple packers it is often impossible or impractical to reach the lowermost packers with a slick-line tool. This lack of a fast and inexpensive method for controlling valves in a packer is a constraint on well design and production operations.
Conventional packers are known such as described in U.S. Pat. Nos. 6,148,915, 6,123,148, 3,566,963 and 3,602,305.
All references cited herein are incorporated by reference to the maximum extent allowable by law. To the extent a reference may not be fully incorporated herein, it is incorporated by reference for background purposes, and indicative of the knowledge of one of ordinary skill in the art.